Impact on salinity of Chilika Lake due to changes in the inlet system

摘要

In Chilka lake a new inlet was formed due to natural coastal processes at Gabakunda in August 2008 at 1 km north of the existing inlet at Sipakuda. Present study deals with 2-D mathematical model (MIKE21) studies with two inlets to assess the hydrodynamic changes and salinity variations due to the formation of new inlet at Chilika lake. Predicted tide, monthly average inflows of the rivers and observed salinity are used for the model studies with a constant width of inlets throughout the simulation period. Newly formed inlet has a dominant role in contributing tidal exchanges over Sipakuda inlet. Decrease in tidal prism with two inlets is observed in comparison with that of single inlet system at Sipakuda, which leads to decrease in salinity of about 10 ppt in all the sectors of the lake. Lake salinity is improved by preserving tidal exchange by maintaining the cross sectional area and depth of the inlets.